Piston and cylinder assembly



5 Sheet-Sh'eet 1 F. F. WARNER E'l'AL PISTON AND CYLINDER ASSEMBLY Feb.2s, 195o Filed Jan. 29. 1944 Feb. 28, 1950 F. F, WARNER Erm. 2,498,971

PISTON AND CYLINDER ASSEMBLY Filed Jan. 29, 1944 i 3 Sheets-Sheet 2ATTORNEY Feb. 2s, 195o F, F, WARNER AL 2,498,911

PISTON AND CYLINDER ASSEMBLYl Filed Jan. 29, 1944 l 3 Sheets-Sheet 5 farf A INVENTORS; A omega-173:; la@ CHM n FLOYD l- WARNER MAR# L; @Roo/f6fwn Ju U5 BARDELME/ER Patented Feb. 28, 1950 PISTON AND CYLINDERASSEMBLY Floyd F. Warner, Mark L. Brooks, and Julius E. Bardelmeier,St.`Louis, Mo.

Application January 29, 1944, Serial No. 520,354

Claims.

This invention relates to improvements in cylinder and pistonassemblies, and more particularly to improved construction, assembly,and method of operation of a piston, a cylinder in which the pistonoperates, and one or more abutment elements serving to seal the endzones of, or constitute a partition across the cylinder.

Expressed somewhat more concretely, an important object of the inventionis attained in an assembly of cylinder, piston and gate or abutment,through which the piston passes with no appreciable loss of uid from thecylinder of or in which the gate abutment constitutes a closure.

A further important object of the invention is attained in an assemblyof the type referred to in the preceding object, and in which a gatetype abutment may be primarily operated by the piston incident totraversal of the abutment thereby.

An additional object of the invention is attained in the provision of asubstantially co'ntinuous running seal between a gate type abutment anda piston operating through such abutment.

The foregoing and numerous other objects will more clearly appear fromthe following detailed description of a presently preferred embodimentof the invention, considered in connection with the accompanyingdrawing. Since it is to be understood that numerous variations may bemade in valving provisions, details of cylinder and valve constructionand arrangement, and means for lubrication of the various moving parts,the present description and claims are conned to those structuralfeatures of the invention having to do with the piston, cylinder andabutment features.

In the drawings:

Fig. 1 is a half sectional view taken in a plane including the axis ofrotation of certain of the rotary elements and a center power shaft;

Fig. 2 is a sectional elevation taken in a plane normal to the axis ofrotation and medially of a rotor and one of the cylinders or units ofthe assembly;

Figs. 3, 4, 5, 6 and 'l are diagrammatic illustrations showing, as basedon the general structural arrangement of Fig. 2, but omitting details,different positions of two pistons each traversing a pair of cylinderchambers, and illustrating one mode of application of present principlesto they operation of a rotary-piston type of internal combustion engine;

Fig. 8 is a diagrammatic illustration of an abutment gate-actuating camprofile, developed in a single plane for a better understanding ofopening and closing movements of the one or more abutment gates;

Fig. 9 is a top or plan View of a preferred form of piston, and

Figs. 10A, 10B, 10C, 10D, 10E and 10F represent a series of gate portopenings successively attained as the abutment gate is moved from fullyclosed, to fully open position to permit passage of one of the pistonstherethrough, this series of figures, diagrammatic in nature, similarlyrepresenting successive cross sectional contours of the leading orcamming portion of one of the pistons, the locations of correspondingsections being indicated by lines AA, B-B, CAC, D-D, E-E, and F-F inFig. 9.

Referring now by characters of reference to the drawing, and rst toFigs. 2 through'7, two` pistons are respectively numbered I and 2, the

more detail. These pistons both operate in a true circular path, andwithin one of a plurality of annular, or more particularly, toroidalcylinders 3.

Referring now to Fig. 1, the assembly may include a casing I0 providedwith suitable shaft bearing portions II in which is operable a powershaft I2. This may, for reasons not material to the present disclosure,be of hollow form as shown. Secured to the shaft I2 against angulardisplacement thereon, are shown a pair of rotors I3 and I4, eachcharacterized by a hub portion I5 which may be keyed or otherwisesecured (by means not shown) to the shaft I2. portions of rotors I3 andI4 serve peripherally to carry the pistons I and 2, for which purpose,at diametrally opposite positions on each rotor web, there is provided apiston-mounting projection I6 apertured to receive a piston pin I'I,this mounting being preferably but not necessarily in the nature of apivotal mounting.

Just inwardly of its periphery each of the rotors I3--I4 is providedwith a pair of annular projections 2IJ. As will readily appear from Fig.1, each such projection interts'a corresponding annular recess 2I ofangulate section, formed in a sealing ring element 22, there being apair of the rings 22 disposed oppositely to each other on opposite sidesof each rotor periphery, and the rings 22 being retained in andsupported by an annular ring-pocket block 23. The lower wall of theblock 23 is slotted as at 24 to permit operation in the slot, of -theweb of the adjacent rotor. The rings 23 coact with projections 20 insealing relation either by resilience of the ring elements, or ifdesired, by biasing effect of abody of fluid The web kept underhydraulic pressure, lbehind one or both of the rings. For this purposethere is shown a space 25 between at least one of the rings, and theadjacent wall of the element 23. The ring retainer block structure ispreferably supported by and secured to an annular block which, althoughobscured in Fig. 1 by certain of the abutment elements, consistspreferably of a casting or like body in which are formed the toroidalcylinders. It will have appeared that, from-the provision of the sealingrings 22, coacting with the extreme peripheral portions of the rotors I3and I4, such peripheral portions are provided with a running seal overtheir full perimeters, thus preventing escape in a radial inward.direction of the various fluid contents of the cylinders 3 such asotherwise might occur `where the pistoncarrying projections or bracketsI6 extend into the cylinders. Depending upon the desired application andservice requirements of the asn sembly, any practical plurality'of thecylinders 3, each containing operatively, one or more of thepistons Iand 2, may be arranged in axial adjacence; it is now obvious that, if`desired, one or `more lcylinders of this general type maybe employed.sayv as the cylinders ofanzengine of rotary piston type, while one ormore additional such cylinders maybe employed as pumps,:com pressors,superchargers and as operating accessoriesto the enginexproper,considered as a prime mover. The description will, for brevity, bedirected to a compressor piston, operable in a toroidal cylinder.

Anv annular cylinderfor assembly thereof may be provided in diametrallyopposite zones eX- teriorly of the cylinder proper, with a. manifold orreservoir structure-.two of whichare shown irl-Fig. 2,:and sincel theseare or may, be, identical, although reversed in gposition,-a descriptionof one will suffice for both. In thisconstruction a cell or 'chamber 30is formed within anvelement 3I provided -with external cooling ns orribs .32, provided also with a, tapped aperture 33 for the receptionfofa gauge or other accessory and-With a pair of substantially. cylindricalor even preferably-tapered lcylindrical valve seats,-134 and 35, for theoperative'reception respectively, ofk rotary valves 36 and31. Each ofthevalves -contains a transverse fluidy passage 38, and the Istructurejustdescrbed maybe conveniently mounted-on the cylinder blockstructure,as bybolts or screws 4U. Although-it maybe noted aspreferable'to actuate the valves-36 and 31 withra quick Oscillatingmotion, andto operate valve 31 entirely afterfull opening and fullclosing of valve YI-, the specic, preferred means of lvalve actuationbeingthelsubject of a contemplatedl application for patent-on thisfeature per se, need not. be further described` herein.

It is a preference to utilize the described pair of pistons I and 2operating continuously in1such manner that. each fully traverses thelentire an nular space or two `half-annular chambers,v of each'cylinder.With this'arrangement there is preferably provided azpair ofabutments'generally indicatedin Fig. 2 at 45 and 46. In-preferred formeach abutment 'consists of a reciprocally actuated, slidably movablegate, the gate element proper of which is indicated at 41 (Fig. 1) andwhich is arranged to reciprocateV from thepositionshown by dotted linesin Fig. 1, downwardly in. that figurev to the full-open position=shownby full lines but iny section.

.As will-appear, actuation .of each of the gates 41 iseffected`primarilyby the pistons in passing therethrough, although for thepurpose of initiating the movement of the gate barely in advance of eachpiston reaching the gate, there is preferably employed a cam arrangement(later described) serving to eifect the movement of element 41downwardly (Fig. l), return thereof to its initial or closed positionbeing effected by a gate return spring or plurality thereof 50, providedwith an enclosing housing 5I of cylindrical form, this housing being inturn reciprocally movable within a stationary holder 52. A plural- `ityof the spring and housing assemblies may, if desired be employed foreach gate.

As a means tending to bias the lower margin :53 of the gate, into closesealing engagement with Vthe upper margins of the sealing rings 22, andVsimilarly with the upper margins of the ring carriers 23, there areutilized a plurality of coil fspringsl which are kept under somemoderate loading between the innermost margins of the elements .3I ,andthe upper or outer margin 55 of the slidable-.gate member 41.

Proceeding nowto a description of the gateactuating cam means, apreferred embodiment thereof includesa plate or disc generally indicated at 60, which is carried by and securely assembled to the shaft I2as by a key or any other lsuitable locking means (not shown) so that thecamv plate operates in assured and fixed timed relation vwith the rotorssuch as i3 and I4, and

hence in a definitely timed relation to the pistons.

-Mounted so as to project substantially at a rightangle to the disc 6U,is a cam element 5I. Forreasons of effecting a precision adjustment ofthe cam 6I with respect to the disc SEI, the canris preferably formed asa separate element andA secured to the `disc as by a plurality ofscrews, of which one is shown at 62. The screw-receiving apertures inplate 6U may, if desired, be somewhat enlarged to'permit some moderatedegree of'angular adjustment of the cam 6I with respect to cam plateEll. It will have appeared that the movable gateelement proper 41 of theabutment assembly, is somewhat undercut in the region of its innermostright hand margin as indicated at 63, whereby portion B3 serves, ineffect, as a follower for cam 6I. It will be understood that, although asingle cam assembly is described, '1 the requisite plurality,corresponding tognumber of gate elements, will be utilized.

A preferred design of profile of cam 6I will hereinafter be moreparticularly described, since it will be better understood following adiscusw sion of the structure of pistons I and 2. As heretofore noted,the pistons constitute, by preference, the primary gate-actuatingagencies, and in effect themselves serve as `gate-operating cams so'asto supplement the operating inuence of cam 6I, all as will later moreclearly appear.

It will have been noted from Fig. 1 that the gate 41 is ported to enablepassage through the gate, of the several pistons in each of thecylinders 3 controlled by the given abutment gate. These ports areindicated in dotted lines at te (Fig. l), and by preference, arecircular and each of an area ycorresponding to the transverse sectionalareas of each of the cylinders 3. It will now have become obvious that,as the gate element 41 is slidably shifted in an opening direction (Fig.1), an initial effect will be to create a very minor, merely pin-holeopening adjacent the-side wall of each cylinder. This opening is of ashape approximating that of the overlapping area ofztwopartly superposedcircular elements.

and the extent or area of such opening will be increased until itbecomes fully circular. This occurs when the gate reaches full-openposition, and itsA circular port becomes fully coincident with the crosssection of the cylinder. Closing movement of the gate will obviouslyresult in a reverse sequence of openings of gradually reducing areauntil nearly or completely full closure of the gate takes place. Adiagrammatic showing of the forms of six such successively attainedpiston-openings in the gate, will be seen in Fig. A and those following,it being noted that these correspond closely to successive sectionalshapes of the fore end or nose of the piston, hereinafter described.

Proceeding now to a description of the pistons I and 2, each thereof, aswill appear from Figs; 2 and 9, is of what may be termed a horn shape;since the shaping and construction of the two pistons may be identical,a description of piston I will suce for both. Each piston is preferablyformed on a longitudinal axis which is arcuate, or substantially so, thearc thereof being drawn on a center which `approximates the axis ofrotation of the rotor I3 or I4 by which the piston is carried. Therearmost or trailing one-third or so of the piston, indicated generallyat 10, is or may be close to cylindrical form, departing from a truecylindrical form only by reason of being formed on an arcuatelongitudinal axis. The leading two-thirds or so, being the nose of thepiston, indicated at 1I, is characterizedby an apex portion 12, and isof a gradually increasing cross section rearwardly of the apex back tothe trailing portion 1li. Successive cross sections of piston portion 1Imay be described as derived from successively larger overlapped areas oftwo circles each of the same diameter as the cylinder bore, thesuccessively larger cross sections corresponding to the superposed partsas such circles are successively brought into increasingly overlappedrelation. From the description just given, and from Figs. 10A, 10B, 10C,10D, 10E and 10F, it will appear that the top and bottom of leadingportion 1I are each drawn somewhat to an edge, and that the oppositelateral surfaces of leading piston portion 'II are each formedsubstantially on a true arc, but with the centers of such arcsdistinctly out of coincidence.

It should further be noted that, in the example disclosed, apex 12 isneither located in nor travels along a median of the cylinder, but liesclose to the side thereof identified with the iirst opening of the gateelement 41. From this fact results the skewed or canted aspect of thepiston when viewed in plan, as will appear from Fig. 9.

It is a preference not to attempt any packing provisions for the leadingportion 1I of the piston, but is a distinct preference to provide thetrailing portion 10 with a series of ring grooves, each for thereception of a piston ring or like packing element 13.

While for simplicity of abutment structure each abutment is shown asutilizing but a single reciprocable, ported gate element, it should benoted that the gate shown may be duplicated in each abutment assembly,with the two gates in adjacence, each provided with an individualcamming assembly and with the ports of the two gate elements arranged toapproach, first partly overlap, then be brought into register to passthe piston. Although requiring twice the number of gates otherwisenecessary, and additional cams, an advantage is presented by the doublegate arrangement in that the apex of the piston may Ail) be disposedcentrally thereof, with some simplication of piston production, and thegate opening thus initiated in a region in or near the axis of thecylinder. i

The operations of cam 6I and of piston I, for example in effecting anopening movement of the gate element 41, are thought to have been madeapparent from the description of parts and their relation, but it may benoted for completeness, as a preference, to initiate the openingmovement of the gate slightly in advance (say only one or two degrees)of-actual attainment of gate position by the apex 12 .of the piston.This effect is, now obviously, attained by precision timing of cam 5I,such that the gate will have barely opened no more than to provide asuilicient starting aperture for entrance of the apex 12 of the piston.This eifect, attained by cam prole, will best be seen from the diagramof Fig. 8 wherein there is shown as a planar development, the leadingmargin of the cam lobe and indicated at 80, a toe portion which servesto effect such an initial gate opening. At this point the piston takesover the gate opening movement, and thereafter, and until the piston hascompletely passed through the port of the gate, the piston serves as thegate-actuating agency in conjunction with the cam, with the now obviousadvantage that there is thus assured a running seal between the marginof the port '65 in the gate, and the periphery of the piston portions 1Iand 10 in this sequence. It may be desirable, although not in all casesstrictly necesn sary, that the margins of the ports '65 of the gate besomewhat iiared or tapered to enhance the.

area of wiping engagement of the gate port mar gins with the peripheryof the piston portion 1l. It will now be observed from the cam profileof Fig, 8, that, as soon as the piston has attained such a position thatits trailing portion of circular section reaches the port 65 of thegate, no further gate opening takes place, but that the piston remainsnonetheless closely embraced by the port margin and adjacent coactingportion of the cylinder wall, so as to perfect the fluid seal in thisend zone of the cylinder. A further study of the cam prole of Fig. 8will reveal a further desirable feature namely, the provision of thegradual downward trailing slope indicated at 8l of the camming contourof the cam lobe.

It should here be noted that, during cam movement such that the gate isactuated by the toe of the cam lobe, and again during that portionk inwhich the heel of the lobe shown at 8|, is engaged by the gate under theinuence of spring 50, the gate is entirely carnecontrolled by member 6I,but that, during all intervening time being through the angle shown as671/2 degrees in Fig. 8, the gate is primarily or solely under controlof the piston. Although a cam contour is provided between portions 80and 8I such as to effect substantially the same gate opening movement asresults from the piston, the cam profile or lobe nevertheless bears aslightly trailing relation, or otherwise expressed, a slightly spacedrelation, with respect to the cam following portion 63 of the gate.

In the showing of Fig. l, embodying two axially aligned cylinders, theymay be employed for differing purposes, or both as compressor cylinders,acting separately or as successive stages. Where only two cylinders areemployed in adjacence, the disclosed arrangement can best be timedwithin itself and balanced -by angularly displacing the pistons withinone cylinder,

menaant degrees i from:correspondingggpistonsfiof l`thef-.companionicylinder', inzwlflichfcase4 the abutment assemblies iincluding theYgates; will `obviously be 90v degrees displaced in the two cylinders;thus requiring aH separate cam plate,.cams, etc., with gates individualtothe associatedcylinder, but

without departing from the majorelements and features described.Y

When it is considered that under" certain conditions-at'v least :one Ioithe pistons is subject to a'maximumV uid pressuresubstantially at theltimewhenit musttraversethe gate, the advantage, now evident, of beinglableto -fmaintain they end'of the cylinder.substantiallycompletelysealedwhile permitting passage of' the pistonftherebeyond; cannot beover-estimated.l Thisadvantage-particularly evident in and mostimportantly adapted .to .a rotating piston type of'structure 'indistinction from the so-calledoscillating piston types of compressor.

The operation of the present structureis best seen by reference to asimplified 4construction in which is utilized only a single cell or:chamber such as 3D, for example,l the Vone at theleft'hand side'of Fig.2. Such'chamberis equipped with a self-opening, spring-loadedintakevalve (not shown), opening inwardly of chamber 30', and an outwardlyopening spring-loaded discharge valve (not shown) controlling aportout'ofzthe chamber 3D. Thesevalves are not shown since they are or maybe of conventional poppet type..

Let'it be further assumedfthata single gate-'or abutmentassembly such`as 45 is employed, with asingle piston I and .a cylinder 3 inthe form.

'35k Insuch a simplified construction, piston `I will, in the-.positionAshown, be compressing and displacing" fluid through thev of.a fulltorus,omittingfthe right h'and'cell and: adjacent valves.

upper valveSG tothe cell 30; thence outwardly thereofithrough the.poppet discharge valve. As

piston I approaches the gate 45 `the* upper valveY 36 is closed, andthelowerrotary valve 37' is opened. Piston I after traversing thegate,now draws a fresh chargethrough the intake poppet Valve via chamber 30and through the lower r rotary valve 3l. While thus inducing a freshcharge of air, thepis'ton is compressing some air ahead of itself, andas it again approaches the gate, valve 36 is opened and 3l is closed; Atthis time, the poppet discharge valvemay open, depending upon its springloading, but as the piston again traversesthe abutment, valve 31remainingv closed, and vali/e36- again reopens. rIhus the pistondisplaces ahead of itself virtually a'full cylinder of fluid which isdriven outwardly through valve 36, chamber or cell 30, and therefromthrough the spring loaded discharge valve.

It will have appeared that the duplication of the structure described asin Fig. 2, will result inan operationquite similar to that described,except with shortened stroke and 'more `frequent discharge pulsations..Obviously if desired, theplurality of cylinder assemblies, for exampleas shownby Fig. 2; may be used for'increased ca pacity, or may be usedfor consecutive cycles of displacement as in lmulti-stage operation.

It will now appear thatA the arrangement identified with the improvedpiston, cylinder and abutment gate of the present design, serve fully toattain each and all of the several objects hereinabove expressed, aswell-as many' others implied from the more detailed 'description ofparts and assembly.

Although the invention-has been described byA making;particularized..reference to a selected` embodiment of the'. invention,`the :detail of'idee f scription" is to vbe. understood' solely.= in an.in-'- structive rather'. than'in a limiting sense, nu-

merousvariants beingpossible withinfthe scope of the claims hereuntoappended.

We claiml asour." invention:

1. A piston adapted for use in a toroidalcylinder 'andffin traversingrelation .to a' wiping and sealing piston-.gatestructura the pistonbeing characterizedbyra bodyv portion and a nose portion; the ynose.portion .beingY substantially apexed at itsforwardror leading. end,vand being formed. rearwardly `of its'forwardend to present a seriesv oftransverse cross sections each of which exhibitsv a major axis and aminor axis of substantialY symmetry, with'one of said'axes`terniii'iating in dened, substantially rectilinear and longitudinaledge portions.

2..A piston adapted for use ina toroidal cylinder andintraversing'relation to awiping and' sealing piston-gate structure, thepiston including a `body portion and a nose portion, the nose portionbeing provided with a substantially pointed leading end and rearwardlyof its leadin'gend, being characterized by convex, substantially reg..ularlycurved sides,` and presenting'a-seriesfof cross sections eachexhibiting a major anda minor axis of symmetry, the 'convex sides of thenose yportion being drawn on centers each lyingv substantially on aminor' axisof symmetry, and

the convex sides intersecting to form substantially linear, angulate,rib-like protub'erances.V

3. In a piston adapted for use in a toroidal cylinder and in traversingrelation to awiping andsealing piston-gate structure, thepistonincluding a-b'ody portion and a nose portion, the

body portion being substantially cylindrical'and the nose portion beingcharacterizedby convex opposite sides so related as to result ina-seriesv erall'y horn-shape, and constructed to present a.

series of cross sections'increasing in area from the leading end of .thenose portion to a zone near the body portion, each Suchcross sectionexhibiting a major axis and aA minor'axis of symmetry, and the sides ofthe portions of the nose'including the said sections, intersecting alongoppositev margins of the nose in a manner to form in suchVv zones ofintersection, substantiallyA sharp and substantially linear ridgeportions.

5. In a piston of a type for use in a toroidal cylinder and incooperative relation with a wiping and sealing abutment structuretraversed by the piston, a body portion and a nose portion, the

nose portion lhaving an attenuated leadingv end,

and rearwardly thereof being characterizedfby a series of transversesections each of double convex` aspect and increasing in both depth andwidth from a zoneY near the leadingend of the nose,

to a zone near the body of the piston, the nose` being thus yprovidedwith distinct angulate ridges along its top and bottom surfaces, thebody being of substantially circular cross sections rearwardly of -thenose por-tion.

6. In a piston adapted for use in a toroidal cylinder and in cooperativerelation with a wiping and sealing piston abutment structure arranged tobe traversed by the piston, the piston including a substantiallycylindrical body and a nose of a generally horn shape pointed at itsleading end, the nose being characterized by a series of transversesections each increasing in area rearwardly of the nose and eachconforming in area and shape to an overlapped area of partly overlappingcircles, the nose portion thereby being formed to present a pair oflongitudinal, substantially linear, angular protuberances along itsopposite sides.

'7. A piston adapted for use in a toroidal cylinder and in conjunctionwith a wiping and sealing piston-gate structure through which the pistonis to pass, the Ipiston including a body portion of substantiallycylindrical shape, and a long nose portion substantially apexed at itsforward or leading end, the nose being convex on its opposite sides butof lesser width than the body whereby it presents a relatively laterallyattened aspect, the convex sides of the nose portion sharplyintersecting each other along opposite margins of the nose, to result insubstantially rectilinear, protuberances of an angular section alongopposite portions of the nose, said protuberances merging into the bodyin a Zone of juncture of the body and the nose.

8. A piston adapted for use in a toroidal cylinder, and in conjunctionwith a wiping and sealing piston-gate structure to be traversed by thepiston, the piston including a body of substantially cylindricalformation and a nose substantially nini-QA a+ H-e Medina cmrl thn nnenhr2-incr nf suhand relatively sharp protuberance along each of twoopposite portions of the nose and extending substantially from thepointed leading end 'of the nose back to the body, the nose being formedon an axis curved on substantially the same center as the toroidalcylinder in which the piston is to be used, the said axis of the nosebeing angularly related to the axis of the piston body in such mannerthat one side of the nose and one side of the body both liesubstantially tangent to a common plane, and so formed that the 'apexedend of the nose lies substantially in said plane of tangency.

10. In a piston and cylinder assembly adapted for use as a compressor, atoroidal cylinder, a valved transfer chamber external to butcommunicating with the toroidal cylinder, and provided with a pair ofpassages from the chamber to said cylinder, a valve in each of saidpassages, a piston-wiping and sealing gate structure or abutment locatedto extend across the toroidal cylinder between the said passages, and apiston operating in the cylinder and in traversing relation to saidwiping and sealing piston gate structure, the piston being characterizedby a body portion and a nose portion, the nose portion beingsubstantially apexed at its forward or leading end, and being formedrearwardly of its forward end to present a series of transverse vcrosssections, each of which exhibits a major axis and a minor axis ofsubstantial symmetry, with one of said axes terminating in defined,substantially rectilinear and longitudinal edge portions, the pistongate structure including cooperating elements adapted to define a portfor the piston which port is of variable shape and area as traversed bythe

